When we meet someone for the first time, it’s common for us to hone in on the facets of that person’s personality that most resemble our own.  So, someone who is friendly and outgoing is likely to see those traits in others too.  It’s a phenomenon known as the “assumed similarity effect”, with psychologists believing that because we lack detailed knowledge of the other person, we use our own personalities to fill in the gaps.

Research from Harvard University suggests there may be an additional factor behind this, with reciprocity at the heart of it.  In other words, if we’re friendly and outgoing ourselves, then we’re likely to receive similar behaviors in return.

Bringing out behaviors

The idea is that when we interact with others, we temporarily bring out behaviors that are like our own.  This then results in us inferring that this is really what the other person is like.  It’s a phenomenon the researchers refer to as the “perceiver-elicited similarity effect.”

Interestingly, the researchers also found that there was a dissimilarity effect in evidence.  This occurs when assertive and dominant people result in more passive behavior in others, and similarly, passive people can bring out more assertive behavior in others.

“The idea is, people influence each other when they interact,” the researchers say. “They bring out behaviors in the other person that are in some ways predictably similar, and in others, predictably dissimilar.”

Put to the test

The theory was tested via an experiment in which volunteers were asked to divide into pairs and review and judge a series of photos that depicted works of art.  The idea was that the pairs would influence one another as they worked to judge the artwork.

The volunteers, who were told to assume the role of co-managers of an art gallery, were given just 20 minutes to review 20 different paintings, before choosing three to hang in their gallery.

Before engaging in this task, each participant completed a questionnaire designed to assess their personalities.  When undergoing the tasks, they were videoed so that their interactions could be observed and coded.

“The idea is that personality flows through interpersonal interactions, from who a person is, to how they act, to how others respond to them,” the researchers say.

“You go through life making people a little more like you,” they continue. “The implication is, you have an interaction, you make people more like you, and you see that. This builds up over time. Your world view of what people are like is based on your own personality because of what you bring out in them.”

As such, we can influence our impressions of others just by interacting with them, with our everyday interactions changing how we see other people.